Battery powered electronic shelf labels (ESLs) often must operate several years on one battery charge. Typically, conventional ESLs include a dedicated segmented liquid crystal display (LCD) which displays limited information such as the price of an item and the item's unit cost. As a result of displaying limited information, conventional ESLs include a low duty cycle, low power and low data rate receiver to receive a few hundred bits at a time in order to update the information at an ESL. To conserve power, the low data rate receiver typically remains powered off and periodically wakes up to receive a beacon signal at which point it determines whether to remain powered in order to receive subsequent updated information.
Due to the limited amount of displayable information of a segmented LCD, a conventional ESL has limited use for displaying advertising information such as specials, graphics, and the like. Conventional dot matrix displays, on the other hand, are capable of displaying more information which would be more suitable for advertising. For example, dot matrix displays may display graphics, colored graphics, colored text of varying styles and fonts, and other attractive information. However, the amount of information that is required to update a dot matrix display may require tens of thousands of bits for one update. For example, a low end, 320×240 pixel video graphics array (VGA) single color dot matrix display presently requires 76,800 bits for one update whereas a segmented LCD only requires a few hundred bits for one update. Utilizing the low data receiver approach to updating, the dot matrix display would have to be powered on for periods of time much longer than a conventional LCD, resulting in a high amount of power consumption.
One approach to satisfying large data rates of transmission required by a dot matrix display in an ESL or an advertising display may include employing a conventional high bandwidth transceiver such as I.E.E.E. 802.11, Bluetooth®, and Zigbee® transceivers. To conserve power in order for the ESL or advertising display to operate a long time on one battery charge, the conventional high bandwidth transceivers would have to operate at a very low duty cycle, for example, awaking from a sleep mode once every ten minutes. Retailers, who deploy ESLs and advertising displays, require that the response time for updating information be performed preferably within seconds of initiating an update. As a result, an ESL or advertising display utilizing the conventional high bandwidth transceiver must wake up periodically in small second increments to determine whether an update has been initiated. Conventional high bandwidth transceivers are burdened by multiple packet exchanges to determine whether an update has been initiated. Furthermore, multiple packet exchanges are also required by conventional high bandwidth transceivers to remain synchronized with a far end device to which it communicates. Thus, conventional high bandwidth transceivers, employed in this way, waste considerable power as compared to a conventional ESL.